Sadly, there are enough people who fall for this scam that they pay their "tax bill" to avoid being arrested or sued not understanding that this is not how the IRS operates. The IRS has reported over $15 million has been collected by this scam being run by hundreds or more foreigners.
They usually ask for payment by i-tunes card. i-Tunes! Stupid, but some people fall for it. IRS does NOT file lawsuits and local police are NEVER involved in federal tax disputes. They rely on the stupidity and ignorance of their victims.